FIELD OF THE INVENTION
This invention relates to a temperature responsive actuator for performing a desired function, such as activating a sprinkler head valve when ambient temperature reaches a predetermined value, also to a novel and improved device for storing, releasing and recovering hydrogen. More particularly, the invention relates to such a temperature responsive actuator making use of a hydride sensor assembly and an actuator assembly wherein when the ambient temperature reaches the predetermined value, hydrogen gas is liberated reversibly from a hydride metal in the hydride sensor assembly and the liberated hydrogen is used to generate gas pressure in a piston or bellows of the actuator assembly which gas pressure, when it attains a certain value, will move the piston or expand the bellows to cause performance of a desired mechanical operation such as operation of the sprinkler head valve.